Wireless sensors, such as the one held here by Dr. Paul Ziehl, are being developed by the College of Engineering and Computing to red flag potentially dangerous flaws in the nation's aging bridges.

Bridges

The Federal Highway Administration estimates that more than 70,000 bridges in the United States are structurally deficient. According to NIST, about 10,000 bridges are built, replaced or repaired annually.

“This underscores the need for a system that will give us ongoing, reliable information about the structural health of the existing bridges so that repairs can be prioritized and accidents averted,” he said.

At the heart of the research is a network of high-tech sensors, including passive piezo-electric monitoring (acoustic emission), which Ziehl has been developing for assessing civil infrastructure. Dr. Victor Giurgiutiu, a professor in the university’s department of mechanical engineering, will lead the research in active piezo-electric sensing, which brings a new and critical dimension to the project.

Passive acoustic emission sensors can detect cracks in steel bridges and measure damage caused by corrosion, for example, in reinforced bridges. Active sensors have the ability to study the structure at will and image damage remotely. Active emission monitoring has been used to detect the structural safety of jets and on railroad tank cars carrying chemicals but has not been used widely in civil engineering.